This invention relates to a method for the fabrication of a bent metal body having a resin layer coated on at least the bent portion thereof.
It is known from the past to form a resin layer over a surface of a metal body, such as a straight pipe, by a fluidized powder coating method in which a metal body preheated to a temperature sufficient to cause melting and hardening of the resin contained in a powder coating composition is immersed in and brought into contact with a fluidized mass of the powder coating composition to form a hardened coating of the resin. In this case, the metal body to be coated is maintained in a vertical position. When the powder coating composition is of an expansion type, the contact of the heated metal body with the fluidized mass of the powder coating composition can form an expanded or foamed layer of the resin over the surface of the metal body.
When such a coating method is applied to a bent metal body, such as an L-shaped pipe, the fluidized particles tend to accumulate on an upper side of a horizontally extending portion of the body so that the resulting resin coating becomes extraordinary thick in that portion.